Agricultural balers gather, compress, and shape crop material into a bale. There are different types of balers which create rectangular or square bales or cylindrical or round bales. Bales can be bound with netting, strapping, wire, or twine. A baler that produces small rectangular bales is often referred to as a square baler. Another type of baler is one that produces large rectangular bales, often referred to as large square baler.
Large square balers have been used in crop harvesting for many years. Large square balers usually utilize a compression system including a gearbox with a crank arm and connecting rod which is attached to a plunger. During each rotation of the crank arm, the plunger compresses the crop in a baling chamber as the plunger moves towards the rear of the baler. Crop is usually metered from a pre-compression chamber into the baler chamber. Large square balers usually include a knotter system for tying twine around the bale before the bale is ejected from the baler chamber. Needles delivery twine through the baling chamber to the knotter system.
A problem with existing large square balers is the lack of protection when an individual needle encounters an obstruction.